The skin is the principal seat of the sense of touch. The skin also provides protection against the physical forces of the environment, such as heat, cold, sun rays, friction, pressure, and chemicals.
Exposure of the skin to these environmental forces can, over time, cause the skin to sag or wrinkle. Hyperfunctional nervous disorders and normal contraction of facial and neck muscles, e.g. by frowning or squinting, can also over time form furrows or bands in the face and neck region. These and other effects of the normal aging process can present an aesthetically unpleasing cosmetic appearance.
Accordingly, there is a large demand for systems and methods which serve to "tighten" the skin to remove sags and wrinkles in the face and neck.
One prior method surgically resurfaces facial skin by ablating the outer layer of the skin (from 200 .mu.m to 600 .mu.m), using laser or chemicals. In time, a new skin surface develops. The laser and chemicals used to resurface the skin also irritate or heat collagen tissue, which is widely present in the dermis. When irritated or heated in prescribed ways, the collagen tissue partially dissociates and, in doing so, shrinks. The shrinkage of collagen also leads to a desirable "tightened" look. Still, laser or chemical resurfacing leads to prolonged redness of the skin, infection risk, increased or decreased pigmentation, and scarring.
Lax et al. U.S. Pat. No. 5,458,596 describes the use of radio frequency energy to shrink collagen tissue. This cosmetically beneficial effect can be achieved in facial and neck areas of the body in a minimally intrusive manner, without requiring the surgical removal of the outer layers of skin and the attendant problems just listed.